Shrinkproofing wool and materials therefor



Patented Dec. 20, 1949 UNITED STATES PATENT OFFICE SHRINKPROOFING WOOL AND THEREFOR m'rnnms John B. Rust, Montclair, N. 1., minor to Mont- Research clair- New Jersey Corporation, a corporation of No Drawing. Application September 7, 1945,

Serial No. also Claims. (Cl. zoo-29.1)

2 mentioned ingredient, there may be mentioned erroneous because while any of the synthetic resins referred to can be applied to wool for example, they are not equally efllcacious in effecting a shrinkprooilng effect. And this is true even of copolymers of butadiene 1.3 derivatives.

Among the objects of the present invention is the production of copolymers particularly valuable in the shrinkprooflng of wool but having other utilities as well.

Further objects include the production of baths, emulsions and compositions containing such copolymers.

Further objects include methods of preparing such copolymersand baths, emulsions and compositions containing them.

Still further objects include methods of treating wool for shrinkproofing. 7

Other objects and advantages of the invention will appear from the more detailed description set forth below, it being understood that this more detailed description is given by way of explanation and illustration only, "and not by way of limitation, since various changes therein may be made by those skilled in the art without departing from the scope and spirit of the present invention.

'In accordance with the present invention it has been found that superior products of highly desirable properties may be produced by commercially economic processes in relatively short periods of time by interpolymerization of a compound having the formula where R; is selected from the group of hydrogen, alkyl and aryl groups, and R: is alkyl or aryl.

Illustrative-of the compound utilized as the first particularly butadiene 1.3, isoprene, dimethyl butadiene, and chloroprene. As illustrative of the unsaturated ketones employed, there may be particularly mentioned methyl vinyl ketone and alpha-substitution products thereof including methyl isopropenyl ketone, methylene amyl methyl ketone, methylene isobutyl methyl ketone. methylene n-propyl methyl ketone, etc. Desirably the total number of carbon atoms in each of the above stated reactants should not exceed twelve. For purposes of illustrating the invention,

examples will be given utilizing butadiene 1.3'with respectively isopropenyl methyl ketone, methylene n-amyl methyl ketone, and methylene isobutyl methyl ketone; since the proportions for producing the most pronounced shrinkproofing effect on wool varies with the copolymerizing ingredient.

While various methods of producing the copolymers may be employed, the most desirable method is to carry out the polymerization in an aqueous medium or emulsion in the presence of a polymerization catalyst. The conditions of reaction determine the speed or reaction velocity as well as the characteristics of the products obtained; although the nature of the interpolymerizing constituents has an important effect on those characteristics; and in some instances the proportions of the copolymer ingredients affect the properties insofar as shrinkproofing of wool is concerned. The preferred process includes the steps of heating a mixture of the constituents to be copoly merlzed with water in the presence of an emulsifying agent and a polymerization catalyst, particularly a peroxide catalyst, in a pressure reactor at a controlled temperature and pH, using agitation to maintain a good emulsion. In this way,

,- emulsions containing the copolymer may be directly obtained and utilized by adjustment and additions as the treating bath for treating the wool to produce shrinkproofing.

By utilizing pressures in excess of atmospheric, the time periods involved may be greatly shortened and the reactions greatly accelerated even at relatively low orders of temperature, to give very satisfactory products. As indicated above, a satisfactory way of carrying out the reaction under pressure is to utilize the stated constituents and reaction mixtures in a closed reactor or reaction vessel, the pressures required being generated under such conditions.

An important consideration in control of the character of product obtained, is the pH at which the reaction is carried out. Desirably, a relatively l6 constant pH should be maintained. The particular pH employed depends upon the particular substances being polymerized and also depends upon the mode of polymerization. Desirably therefore. where the polymerization is carried out in an aqueous emulsion, the pH should be accurately adjusted as by neutralization and stabilized as by means of suitable bulfering agents at that value best suited for the emulsifying agent employed. Depending upon the individual reactants and the conditions of the reaction, the polymerization may be carried out at a controlled pH between 4 and 11. A pH within the range of 7-11 is preferred.

As bufl'ers there may be mentioned solutions of acetates, borates, phosphates, and the like, or mixtures thereof. The pH employed depends in part on the type of emulsifying agent used. Emulsifying agents should be used w ch are stable at the pH concentration employed. With an emulsifying agent which is most efiicient under acid conditions, a pH below 7 is desirable. On the other hand, with emulsifying agents which are most eflicient under basic conditions, a pH above I should be employed. 1

As emulsifying agents, there may be employed a wide range of materials such as sodium lauryl sulfate, sodium alkyl naphthalene sulionate, higher esters of sodium sulfosuccinic acid, sodium oleate, triethanolamine oleate, and the like. The amount of emulsifying agent may be varied depending upon the conditions of agitation. Commonly there may be used about of emulsifying agent based on the water phase, but with vigorous agitation considerably less may be employed. Since soap is the cheapest emulsifying agent, and since its emulsions can be easily broken by addition of a small quantity of acid, it is the preferred emulsifier. The proportion of water to be'used in the emulsion is subject to wide variation. However, avoiding unnecessarily large quantities of water, enables smaller equipment to be employed.

Reaction temperatures of from to 100 C.

may be employed, but more desirably the reaction isgcarried out between temperatures of 30 to 60 (2;; particularly under the preferred conditions of operations as illustrated herein.

As indicated, the reaction is desirably carried out in the presence of a polymerization catalyst and my, suitable oxygen-giving compound may thus be'employed. Preferably the less expensive material such as hydrogen peroxide, ammonium persulfate, .benzoyl peroxide, and the like may be utilized.

While additive agents in the emulsion are not necessary, they areoften advantageous. Protective colloids may be employed such as gelatin, glue, methyl cellulose, agar agar, alginates, pectates, egg albumin, and the like.

5 The temperature, amount of catalyst, emulsifying agent, efliciency of agitation, additive agents, and the like, all have an influence on the velocity of the reaction. When the reaction has proceeded as far as desired, there may be added an antioxidant such as phenyl beta naphthylamine, alkyl aromatic amine, hydroquinone monobenzyl ether, and the like. The presence of antioxidant has an important eifect other than merely as an antioxidant in the usual sense, since the presence of such materials in the emulsions-and baths used for shrinkproofing wool, exert an effect whereby the shrinkproofing is enhanced beyond that obtained in its absence. So that antioxidants in these cases have an unexpected and unpredictable effect.

'C., with oxygen yielding substances such as hy- The inter-polymerization products are produced in latex-like form when the reactions are carried out in aqueous emulsion as indicated above, and such latex-like products may be utilized as such. for example, in the treatment of textiles, preferably after adjustment as indicatetbelow, or they may be employed in other ways.

As formed, the emulsions contain the copolymer in a condition in which it is unsuitable as synthetic rubber or rubber-like material. If coagulated by any suitable means, the emulsions give crumbly materials which cannot be milled or sheeted as on rubber milling equipment in the way that rubber is manipulated. The copolymer is in the form where extensive cross-linking has occurred as further pointed out below.

To enhance such materials for use for shrlnb.

proofing, they may desirably be given an oxidation treatment, preferably while in aqueous emulsion as obtained from the polymerization step, to

convert them into what may be called a prevulcanized condition so that upon deposition of the polymer on, in or about the fibers or textiles, the polymer is in a non-tacky condition and gives a non-tacky deposit. Or the polymer in such emulsions utilized in accordance with the present invention is in a condition inwhich it is substantially insoluble in organic solvents such as benzene, toluene, xylene, carbon tetrachloride, chloroform, and tetrachlorethane, but, however, may be swollen to some extent with such solvents. The vulcanization has been carried, to a point where substantially no soluble polymer remains, but, as stated above, the gel-forming polymer may be swollen to some extent with the stated solvents.

Where such pre-vulcanization by oxidation is be obtained, or the polymer is substantially soluble in common organic solvents at this time, or is incompletely vulcanized, and the emulsion thus prepared is subjected to an oxidative treatment by means of hydrogen peroxide or other substances which liberate oxygen under the conditions of treatment to convert the polymer or copolymer present in such emulsions into a condition where upon deposition on fibers it gives a non-tacky deposit, or gives a deposit which is substantially insoluble in common organic solvents. or is substantially completely vulcanized andin the form of a cross-linked polymer. The first step is carried to a point of substantially complete polymerization, by which is meant little or no monomer is present. The emulsion at this point may be subjected to vacuum or other treatment to remove any volatile hydrocarbons which may be present, before the step of oxidative vulcanization. The term oxidative pre-vulcanimtion may be used to describe the final condition of the polymer in the emulsion without any implication that an oxygen link is necessarily involved.

Such oxidative pre-vulcanimtion may be carried out at temperatures for example of 70-100 drogen peroxide, benzoyl peroxide, ammonium persulfate, acetyl peroxide, butyl hydroperoxide,

butyl perbenzoate, etc. for a period of from 45 minutes to 1% hours. Such oxldative treatment of the emulsion is desirably carried out in the absence of the anti-oxidants, the latter being added after the oxidation treatment has carried to the point desired. This addition of antioxidant is desirable so that further oxidative change will not continue after the material has been applied to the textile.

The emulsions produced as. set forth above may be used for the treatment of wool either as raw wool, yarn, knit, woven goods or mixed goods, etc. The wool to be treated is entered into the bath containing the copolymer produced as set forth above. Water may be added to such emulsions to produce the desired bath content. The bath should contain the copolymer in an amount to give, under the conditions of treatment, a wool having from 1% to 25% of copolymer based on the weight of the wool. The bath is desirably conditioned by adding to it a sumciently strong electrolyte to allow the deposition of the copolymer on the wool fibers. It has been found that in such a bath no deposition of copolymer occurs under ordinary conditions. However, upon the addition of an electrolyte, exhaustion of the bath will take place with varying rapidity, depending mainly upon temperature and electrolyte concentration. Without any limitation by way of theoreticalconsiderations, it is believed that reversal of the electrical charge on the colloidal particles of the copolymer takes place on addition of the electrolyte enhancing the affinity of the copolymer for the fiber. The proportion of the electrolyte added would be insuflicient to account on a theoretical basis for the salting out of the copolymer particles. Thus the effect must be one of electrical charge rather than precipitation by coagulation. When the electrolyte is added to the treated bath there is no coagulation or precipitation even on heating for relatively long periods of time. It is only in the presence of fibers that deposition occurs. This "is additional proof that electrical charge of the particles is involved rather than a salting out'efiect.

The ratio of the copolymerizing ingredients may be varied substantially to produce a shrinkproofing effect; but for optimum results the ratios are different. With isopropenyl methyl ketone the best results are obtained with 5-10% based on the weight of the copolymer while substantial results are obtained with 20-30%. With methyl- .ene n-amyl methyl ketone up to 40% and with methylene isobutyl methyl ketone up to 20% gives excellent results. In general the amount of such copolymerizing ingredient should be less than 40%.

tial limits but sufficient electrolyte should be present to condition the bath so that the bath, although stable in the presence of the wool fibers,

trolytes which produce the desired deposition of the polymer. It has been found that it is possible to deposit the emulsions of the present invention on wool at a pH of 'l or even slightly higher. However, it is preferred to operate at a pH of 7 or below since under these conditions more rapid dispersal is effected. v

The operation is desirably carried out at a temperature sufllcient to give exhaustion of the bath with the particular emulsion being used. This will vary with different emulsions. While lower temperatures may be used, the operation is desirably carried out at temperature ranges from 40 C. to the boiling point of the bath.

The polymer can be applied before or after fulling, weaving, scouring and the like operations. In some cases it can be applied in the dye bath. Mixed goods including wool-cotton, wool-rayon and so forth can be treated by this method without any deleterious effect. If desired the wool may be subjected to a pretreatment, as for example, chlorination or bromination, before being treated in accordance with the present invention.

As emulsifying agents, anionic emulsifying.

agents which are stable at or below pH 7 are preferred. Such emulsifying agents are exemplified by sodium lauryl sulfonate, sodium alkyl naphthalene sulfonates, long chain alkyl sodium sulfonates or sulfates, sodium dioctyl sulfosuccinate and so forth. There may also be used neutral non-cationic emulsifying agents such as mannitol monolaurate, the reaction products of protein derivative products with acid chlorides,

' ethylene oxide reaction products with fatty acids,

The electrolyte content may vary over substanwill deposit the polymer in the presence of the conditioning electrolyte. Thus the electrolyte content may vary from about 25% to about 500% based on the weight of the copolymer present; The following are exemplary: sodium sulphate, chloride, bromide, iodide, sulflte, bisulfate, bisulfite, nitrate, acetate and thelike or the corresponding potassium, lithium, caesium salts, etc. Salts like zinc chloride may also be used where the coagulation does not appear to be too serious since it occurs in small particulate form and the particles may be redispe'rsed by stirring. As such electrolyte water-soluble salts may be used, desirably such salts which do not precipitate the polymer, neutral salts, specifically salts of strong bases and strong acids, particularly inorganic salts are preferred. The term conditioning electrolyte" is used hereinafter to cover such elecfatty alcohols and the like.

Emulsions of the copolymers used in accordance with the present invention are preferably but not necessarily those which have been carried to a polymerization. When 100% polymeruis obtained, considerable cross linking occurs in the polymer with consequent insolubility in organic solvents. Thus a type of pre-vulcanizing of the polymer has been obtained. It is also possible to vulcani'ze the copolymers with mixtures of vulcanizing accelerators such as thiuram disulfide and so forth, vulcanizing agents such as sulfur, dinitrobenzene, alkyl phenol sulfide and so forth, either previously or subsequently to deposition or dyeing into the wool fibers.

The treatment of wool fibers is particularly emphasized herein, although animal fibers such as silk and-protein fibers such as Aralac (a casein fiber) may also be treated in accordance with this invention. I I After treatment in accordance with the present invention, the wool is rinsed and dried. Its

'properties'have'been altered to such a degree that ofthe wool. Thus the deposited copolymer would prevent intertwining of the wool fibers and also permit relatively easy slippage of the fibers one on the other.

The following examples illustrate the invention, the :parts being by weight unless otherwise indicated. A

Example 1.-A series of six isopropenyl methyl parts of water.

by the addition of 1.0 part of sulfuric acid 7 v betone-butadiene copolymer emulsions was prepared. The monomers were used in the propertions shown in Table I.

Table 1 Parish;-

Imulllm Nnmbu' m Rama 1 8 46 2 10 40 a 36 4 I! N s 25 a l) D 7.16 parts of trisodium phosphate dissolved in 980 parts of distilled water. The reactor was closed, allowed to come to room temperature and put in an agitator with a constant temperature bath at 45 C.

All the reactors, except the one containing emulsion #1 were taken out after 16 hours in the agitator. The reactor with emulsion #1 was left in the agitator for a total of 24 hours. The reactors were cooled and opened. Emulsion #1 showed some pressure and foaming, however, none of the others showed any pressure or foaming. In the case of emulsions #2-6 complete polymerization was therefore assumed, which meant a polymer content of 33% for each emulsion. In the case of emulsion #1 the polymer content was checked and found to be 32%. Since this was so close to the theoretical value of 33% latter yaluewas used in the application of the emulsion to textile materials.

Example 2.The six emulsions containing isopropenyl methyl ketone-butadiene copolymers which were made according to Example 1, were applied to hand knot wool samples, approximately 7".x 5" in size. The weights of the samples are shown in Table II. Also listed are the amounts of emulsion used for each sample. These were the amounts which contained a weight of polymer corresponding to 6% ofthe weight of the wool sample to be treated. In each case the weighed amount of emulsion was added to 200 This bath was then conditioned and 1.0 part of anhydrous sodium sulfate. The wool sample was immersed in the bath at room temperature, and the bath was then heated to 60-70 C. and kept at that temperature. After 20 minutes at Gil-70 C. a second portion of 1.0 part of anhydrous sodium sulfate was added. minutes later the baths with samples #1-3 were close to exhaustion and were completely exhausted 10 minutes later, but the baths with samples #4-6 still showed a considerable cloudiness. The

-temperature of these baths was therefore raised to 80 C. for a few minutes, then allowed to come down to Gil-70 C. Within 15 these baths 5 Table II 1 Bullmul- Num fig, Wool Ketune 5 4a mu am sum 10 40 15.50 279 W 15 35 lam 2.71 DO. 20 30 15.4 as: Bed. 25 26 14.45 no -Do. 30 m 15. 17 D0.

VI I-d.

These six samples and one untreated control sample were washed for 6 hours in a washing machineusing25partsofpowderedaoapfor 13,000 parts of hot water at 70 C. The samples were then rinsed and dried.

The extent of the shrinkage and felting eamed bythewashingislistedinTableII. Theresul'ts show a definite shrinkprooflng and fel action of the emulsions which were tried. For I low isopropenyl methyl ketone content the results are very good, but the shrinkprooflng efl ect decreases rapidly with increasing percentage of the ketone in the copolymer, so that only percentages up to 5 or 10% or ketone can be used for maximum eil'ect.

Example 3.A series of methylene n-amyl methyl ketoue butadiene copolymer emulsions was prepared with the monomers in the proportions shown in Table 111.

' Table III e Y Emulsion Nnmbu -Am 1 M i g Bnhdium tone 7. 5 11. i 1- 0 I. Q

.Thebutadiene, which had been over calcium chloride, was condensed in pressure reactors cooled to below -5 C. and the exact 'amounts of butadiene were weighed out in the After 24 hours in the agitator the reactors were taken out, allowed to cool to room temperature and opened. No pressure was noticed on opening.

Complete polymerization could therefore he luv sumed for all four emulsions, which meant a glymer content of 33%, for each of these emul- Example 4.The four emulsions made according to Example 3 were applied to 10" x 10" samples of wool flannel, on which four lengths of 8" each had been marked, two lengths in the direction of the warp, two lengths in the direction of the fill.

The wool samples-weighed approximately 12.5

parts. An amount of emulsion containing a weight of polymer corresponding to 4.5% of the weight of the wool sample to be treated was added to approximately 250 parts of water (20 times the weight of the woolsample) and 2.0 parts of 50% acetic acid. Approximately 3.5 parts of anhydrous sodium sulfate (26.5% of the weight of the wool sample) were dissolved in 50 parts of water.

The wool sample was wetted in water at 30 C. for minutes and immersed in the bath at room temperature containing the emulsion and the acid. The bath was then heated to 60 C. in the course of minutes. Half of the salt solution was added, and the bath was kept at 60 C. After 15 minutes the second half of the salt solution was added. Approximately -40 minutes after the second salt addition the baths were exhausted. The samples werethen rinsed, dried and measured.

These four samples and one untreated control 1 sample were then washedin a washing machine using parts of powdered soap for 18,500 parts of hot water at 70 C. The samples were then rinsed and dried, and the marked lengths measured.

The results shown in Table IV indicate clearly that all four emulsions, which were tested, were excellentshrinkprooflng and feltproofing agents.

Example 5.Two emulsions containing copolymers of methylene isobutyl methyl ketone and butadiene were prepared. The monomers were used in the proportions shown in Table V.

Table V Mitt e y ene Parts Emulsion Number isobutyl I 7 Methyl Butadiene ketone The butadicne was passed over calcium chloride and condensed in pressure reactors cooled to below -5 C. The exact amounts of butadiene were weighed out in the reactors, and the methylene isobutyl methyl ketone was then added, followed by 50 parts of a buffer solution of pH 11. 2.5 parts of a 10% ammonium persulfate solution and 2.5 parts of sodium lauryl sulfate, The bufler solution of pH 11, consisted of 35.8 parts of disodium phosphate and 7.16. parts of trisodium phosphate dissolvedin 980 parts of distilled water. The reactors were closed, allowed to come to room temperature and put in an agitator with a constant temperature bath at 45" C.

After 24 hours in the agitator the reactors were taken out, cooled to room temperature and. opened. A slight pressure was noticeable but complete polymerization could still be assumed. The polymer content of both emulsions was therefore 33%%. v

Example 6.-The two emulsions made as described in Example 5 were applied to 10" x 10" samples of wool flannel on which four lengths of 8" each had been marked, two lengths in the direction of the warp, two lengths in the direction or the fill.

The samples weighed 13.03 parts and 13.07 parts respectively. An amount of emulsion containing a weight of polymer corresponding to 4.5% of the weight of the wool sample to be treated was added to 260 parts of water (20 times the weight of the wool) and 2.0 parts of acetic acid. 3.46 parts of anhydrous sodium sulfate (26.5% of the weight of the wool sample) were dissolved in 50 parts of water.

The wool sample was wetted in water at 30 C. for 10 min. and immersed in the bath containing the emulsion and the acid at room temperature. The bath was then heated to 60 C. in the course of 15 minutes. Half the salt solution was added,v and the bathkept at 60 C. After 15 minutes at 60 C. the second half of the salt solution was added. Exhaustion occurred 15-20 minutes after the second salt addition. The

samples were rinsed and dried, and the marked lengths were measured.

, Table VI Mlzillxl'tlS Per Cent e yene Pm hrinkage Sam is Number lsobut l Feltin p methyyl Butadiene I ketone Warp Fill 1 2.5 225 11.4 10.4 Slight. 2 5.0 20.0 11.4 10.0 o. 3, (llontrol Sam- 32.2 12.0 Bad.

p 0. r I

These two samples and one untreated control sample, which had also four lengths of 8" each marked on 'it, were then washed for 6 hours in a washing machine using- 35 parts of powdered soap for 18,500 parts of hot water at 70 C. The samples were then rinsed, dried and measured.

The extent of the shrinkage and felting caused by the washing is listed in Table VI. The two' treated samples show a definite improvement over the untreated sample. However, the results are not quite as good as some of those obtained with'other ketone copolymers described in Examples 2 and 4.

Having thus set forth my invention, I claim:

1. A bath suitable for shrinkproofing wool with substantially normal hand which comprises an aqueous substantially stable emulsion containing a synthetic copolymer of polymerization, of butadiene 1.3 and from 5 to 40% by weight of the copolymer of an unsaturated ketone containing not more than twelve carbon atoms and having the formula CH2=CR2-CO.R3 where R2 is selected from the group consisting of hydrogen and alkyl groups and This alkyl, the copolymer being present in amount to give 1 to 25% by weight'of copolymer deposition on the wool, a non-cationic emulsifying agent, stable at a pH below 7, and at least, 25% by weight on the copolymer of a water-soluble neutral salt of an alkali metal as conditioning electrolyte, the pH ofv the bath being below 7.

2. A bath as set forth in claim 1, in which the ketone is isopropenyl methyl ketone not exceeding 30% by weight of the copolymer.

3. A bath as set forth in claim 1, in which the ketone is methylene n-amyl methyl ketone not exceeding 40% by weight of the copolymer.

11 4. Abathessettorthinclnim Linwhiohthe ketone' is methylene iaobutyhmethyl ketone not exceeding 20% by weight of the oopolymer.

5. .4 both as set forth in claim 1, in which the emulsifying agent is anionic. 5

JOHN B. RUST.

REFERENCES CITED The following references are of record in the 1 tile 01 this patent:

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